“Flow batteries” have been considered for the storage and distribution of electrical energy. Like conventional batteries, flow batteries convert chemical energy of electro-active materials into electrical energy. However, in contrast to conventional batteries, flow-batteries typically store electro-active materials externally with respect a cell stack, and the electro-active materials are usually only introduced during battery operation. Typically, the electro-active materials are in liquid form and are pumped to a cell stack when the battery is being operated. Accordingly, flow-batteries can confer a number of benefits with respect to conventional batteries including they may be safer insofar as the electro-active materials are stored externally and they may be rapidly recharged by simply substituting the (typically liquid) externally stored electro-active materials. The viability and practicability of flow-batteries can be improved if they can more efficiently store and provide electrical energy, and if they can be produced more cost-effectively. Thus, there exists a need to develop more efficient and more cost-effective flow batteries.